Methods for preparing oxindole and thio-oxindole compounds, particularly 5-pyrrole-3,3-oxindoles, which compounds are useful as precursors to various pharmaceutical compounds are provided.
The synthetic routes to many useful compounds, including pharmaceutical drugs, typically entail a large number steps. However, the presence of numerous steps in the synthetic route to the desired product tends to result in lower yields of the product even before purification.
Many useful compounds in the art have an oxindole backbone and particularly a 3,3-disubstituted oxindole backbone. Of particular interest is 5-(7-fluoro-3,3-dimethyl-2-oxo-2,3-dihydro-1H-indol-5-yl)-1-methyl-1H-pyrrole-2-carbonitrile, which contains a 3,3-disubstituted oxindole backbone. In fact, the current route to 5-(7-fluoro-3,3-dimethyl-2-oxo-2,3-dihydro-1H-indol-5-yl)-1-methyl-1H-pyrrole-2-carbonitrile involves at least 6 steps to give an overall yield of 6%.
What is needed in the art are alternate methods for preparing 3,3-disubstituted oxindole compounds and the intermediates utilized in preparation thereof.